【作者】 林瀚智；

【导师】 秦松； 匡廷云；

【作者基本信息】 中国科学院研究生院（海洋研究所） ， 海洋生物学， 2012， 博士

【摘要】 藻胆体是蓝藻和红藻体内主要的捕光蛋白-色素复合物，它是与细菌叶绿素、叶绿素蛋白-色素复合物同时存在的放氧光合生物的两大捕光蛋白-色素复合物。藻胆体与叶绿素蛋白的区别是1藻胆体通过连接多肽锚定在类囊体外，并与反应中心相连，2其主要的光能吸收范围在450-650nm范围，与叶绿素、细菌叶绿素的吸收光谱不同，3其光合色素（藻胆色素）与蛋白通过共价键连接，而叶绿素分子则通过氢键、范德华力等分子间弱相互作用与蛋白质骨架相连。对于藻胆体的结构的研究始于上世纪70年代，主要利用电子显微镜进行观察，但由于技术条件所限，其分辨率非常之低，只能反映其复合体的轮廓。随着针对生物样品的电子显微镜的发展以及冷冻电子显微镜技术的建立与成熟，生物大分子的高分辨率的结构解析成为了可能。因此，我们通过透射电子显微镜技术对现存已知的所有类型藻胆体进行了结构观察，得到更高质量的半椭球形、半圆盘形（三核六杆、二核六杆、五核八杆）、束状、块状藻胆体的负染结果，这为获得高质量的电镜三维结构提供非常坚实的基础。在此之上，我们对嗜热蓝藻Thermosynechococcus vulcanus和盐泽红藻Porphyridium aerugineum的藻胆体进行了更为深入的研究。通过对Thermosynechococcus vulcanus的负染二维平均的单颗粒分析，我们发现其三核六杆的核部分的两肩各存在两个蛋白，推测其为含有色素的蛋白。通过冷冻电镜的观察，发现藻胆体颗粒多呈错位排列在气-液界面上，这种极性-非极性界面的排布方式可能与细胞内膜内-膜外的排列类似。对盐泽红藻Porphyridium aerugineum的二维平均，使得为通过冷冻电镜深入揭示其三维结构提供了很重要的结构信息和技术基础。作为国家应急科技攻关的一部分，基于以往科学家所获得的遗传学研究基础，我们采用几个分子遗传学标记对黄海绿潮进行了研究，提示其可能为同一种群，同时因早期卫星又监测不到绿潮的位置和规模，我们提出在春季黄海存在一个暂时稳定的栖息地，为浒苔提供营养、适宜温度供其迅速生长繁殖的假说。经过MODIS的SSH和SST数据分析，我们发现在春季黄海存在一个直径在100km左右的冷涡，其旋转过程可能将海底的营养“泵”到上层水体中供浒苔生长，这揭示其可能的一种时空动态过程，也为揭示世界范围内的绿潮爆发的整个生物-物理-化学偶联的动态过程提供了新线索和新思路。更多还原

【Abstract】 Phycobilisomes are cyanobacteria and red algae’s the main light-harvesting protein-pigment complexes. It exists with bacterial chlorophyll, chlorophyll-protein-pigmentcomplex at the same time, the oxygen-evolving photosynthetic organisms, twolight-harvesting protein-pigment complex. Phycobilisomes and chlorophyll-proteinare different:1phycobilisomes are connected with reaction center by peptide linkerproteins,2the absorption of phycobilisome’s light absorption range is450-650nm,and chlorophyll and bacteriochlorophyll have different spectra since red algae can livein a nearly200-meter-deep ocean, so it can be very efficient to capture low-light450-550nm light,3photosynthetic pigments (phycobilin) connect with proteincovalently while chlorophyll molecules connect with protein backbone throughintermolecular hydrogen bonds, van der Waals and other weak interactions.For phycobilisomes structure, the research began in the1970s. The technology ofelectron microscopy was applied, but limited due to technical conditions, theresolution is very low. As for the development of electron microscopy of biologicalsamples and cryo-electron microscopy techniques, it is possible to establish andmature, high-resolution structural analysis of biological macromolecules. Therefore,by transmission electron microscopy, existing known all types of phycobilisomesstructure was observed. Higher-quality of semi-ellipsoidal, semi-disc, bundle andblock phycobilisome were obtained. Moreover, we conducted a more in-depth studyof the thermophilic cyanobacterium Thermosynechococcus vulcanus and red algaPorphyridium aerugineum phycobilisomes. Thermosynechococcus vulcanusresurgence of two-dimensional average single particle analysis, we found that on itstriple-core shoulders, there are two proteins, presumably as a protein containingpigment on each shoulder. Frozen electron microscopy (cryo-EM) observationsfound that phycobilisomes particles mostly were dislocation arrangement in the gas- liquid interface, this polarity-the arrangement of non-polar interface may be similarto the intracellular membranes-outer membrane arrangement. Marine red algaPorphyridium aerugineum’s two-dimensional average was obtained, making a veryimportant structure to reveal its three-dimensional structure by cryo-EM in-depthinformation and technical basis.Green tide in the Yellow Sea as part of a national emergency scientific andtechnological multi-level genetic research suggests may be the same population. Weproposed a temporary existence in the spring, the Yellow Sea stable habitat, providenutrition for Ulva prolifera, the optimum temperature for rapid growth andreproduction hypothesis. After the MODIS SSH and SST data analysis, we found thatthe existence of a cold eddy diameter of about100km in the spring of the Yellow Sea,and rotation transfer process may be nutrition "pump" of the seabed to the upper watercolumn for the growth of Ulva prolifera, which reveals the possible kinds ofspace-time dynamic process, also provides new clues to reveal the dynamic process ofthe outbreak of the green tide in the world within the scope of the entire biological-physical-chemical coupling.更多还原